1. Field of the Invention
This invention relates to a medical diagnosis assistance system, a medical care assistance device, and a medical care assistance method. In particular, this invention relates to a medical diagnosis assistance system, a medical care assistance device, and a medical care assistance method that are used in the medical care of central nerve diseases.
2. Description of the Related Art
With recent acceleration of the aging of society, the number of patients who have central nerve diseases such as Alzheimer's disease, Parkinson's disease, and the like has been increasing. Throughout the world, effort is continuing toward determining a cause, an early diagnosis, and the establishment of a method for medically treating illnesses related to central nerves. However, because understanding of the brain is insufficient, one can say that the status of these is still at the early stages.
Image examination by modality has been used as a means of effective medical care for diagnosis and research on central nerve diseases, such as MRI (Magnetic Resonance Imaging) devices and nuclear medicine diagnostic devises. Such nuclear medicine diagnostic devises includes PET (Positron Emission Computed Tomography) and SPECT (Single Photon Emission Computed Tomography) in addition to others.
Modality—which highly differentiates soft parts, such as using MRI devices—is applied in observation for morphological atrophy of the brain. Modality, which is capable of creating functional images, such as using fMRI (functional MRI) or the nuclear medicine diagnostic devises is applied in observation for the active state of a brain.
Recently, there has been significant development in the field of molecular imaging. Molecular imaging is categorized into two techniques. The first technique is the creation of the image of a nanometer-level molecule using light or X-rays, which is literally “molecular imaging.” Fluorescence microscopes and X-ray microscopes are examples of this technique. This technique is mainly used in laboratories because of the problems of energy invasion depth into a body to image and also of exposure to nuclear radiation.
Meanwhile, the second technique of molecular imaging is one that uses the collection of peculiar labeling agents (ligand) for specified molecules, cells, and tissue. This second technique is for imaging the presence and behavior of tiny amounts of molecules via the amplification of signals by adding contrast agents such as RI (radioisotopes) to ligand. An example of this technique is nuclear medical examination (which uses PET and SPECT) by administering RI labeling agent. MRI molecular imaging, which uses improved molecular peculiarity by adding ligand to nanoscale magnetic material such as SPIO (Super-Paramagnetic Iron Oxide), is also an example of this technique.
The second technique results in low resolution, but there is high expectation for using this technique in clinical studies, because it can create images on presence and function of molecules within a living body. Especially at present, technology such as PET-CT has attracted attention whereby high-resolution morphological images (CT image) are combined to improve the low-resolution of functional images (PET image) so that high-resolution morphology can be displayed overlapping with functional information.
While approaches using imaging are being developed, studies from the perspective of substances are showing progress. Central nerve disease is mainly caused by functional disturbance, or metabolic disorders due to the accumulation of waste that accompany aging. Now, approaches for finding ways of medical treatment and tracing the causes of central nerve disease by studying this waste are beginning to show progress.
One result that has been attracting attention recently is β-amyloid (beta amiyloid) (Aβ), which is regarded as one substance that causes Alzheimer's disease. β-amyloid is sometimes referred to as β-amyloid plaque, amyloid-β, or amyloid-β protein. Aβ is beginning to be known to precipitate as crystals in the brain, and to accelerate cognitive disorders while precipitating.
Therefore, Aβ is designated as a target molecule (detection target molecule) and contrast agents are added to ligands that specifically accumulates to this. As a result, the accumulation of Aβ in the brain in the early stage that is difficult to be detected morphologically, can be detected. Thus, diagnosis of Alzheimer's disease will be possible at an extremely early stage, and means for suppression of the progression of symptoms can be initiated at an early stage. Furthermore, the relationship between Parkison's disease and abnormal secretion of dopamine is well known as a common knowledge. These prior arts related to a material approach are disclosed in Japanese Unexamined Patent Application Publications 2001-352991, 2004-157124, 2004-261172, and 2003-199460.
At the same time, MIT (Minimally Invasive Treatment) is gaining attention in the field of medical treatment. Examples of this means include shockwave calculus fragmentation therapy, cyber knife, and IMRT (Intensity Modulated Radiation Therapy).
Shockwave calculus fragmentation therapy is a method of medical treatment whereby strong shockwaves such as ultrasonic waves are irradiated from outside the body to crush crystals inside the body (refer to Japanese Unexamined Patent Application Publication 2005-261599, for example). Cyber knife and IMRT enable the highly effective medical treatment of local cancer parts as well as exposure to nuclear radiation along the irradiation pathway to decrease, by irradiating nuclear radiation from a plurality of directions based on a three-dimensional treatment plan (refer to Japanese Unexamined Patent Application Publication 2002-267754, for example).
Meanwhile, a study has been advanced that attempts to solve the substance causing Alzheimer's disease Aβ by irradiating ultrasonic wave energy low enough to have little impact on central nerve tissue. Furthermore, studies of a drug delivery system that performs medical treatment by transporting medicine to the target parts of the brain have been advanced (refer to Japanese Unexamined Patent Application Publication 2000-504697, for example).
However, with the prior art, we have been unable to discover the specific relation of what kind of effect wastes and similar substances existing in the brain have on central nerve functions as well as body function. While the accumulation of substances is in progress, we have been unable to predict what kind of impact can be made on the central nerve and body functions in the future. Therefore, it has been difficult to diagnose nerve-related disease in an early stage and to predict the status of clinical conditions, with high precision.
In addition, when performing medical treatment for central nerve disease such as the above, substances such as Aβ are accumulated in a plurality of parts within the brain. In this case, it is preferable to optimize timing and the order of medical treatment by considering the quantity of accumulated substances in each part and the level of importance of the body or central nerve function corresponding to each part. However, it has been difficult to improve the safety and effectiveness of medical treatment for central nerve disease because the prior arts have been unable to discover the relationship between substances existing within the brain and the central nerve or body function corresponding to a brain part.